First-principles modeling of the temperature dependence for the superlattice intrinsic stacking fault energies in L₁₂ Ni_75-xX_xAl₂₅ alloys

Stronger and more resistant alloys are required in order to increase the performance and efficiency of jet engines and gas turbines. This will eventually require planar faults engineering, or a complete understanding of the effects of composition and temperature on the various planar faults that arise as a result of shearing of the γ^' precipitates. In the current study, a combined scheme consisting of the density functional theory, the quasi-harmonic Debye model, and the axial Ising model, in conjunction with a quasistatic approach is used to assess the effects of composition and temperature of a series of pseudo-binary alloys based on the (Ni_75-xX_x)Al25 system using distinct relaxation schemes to assess observed differences. Our calculations reveal that the (111) superlattice intrinsic stacking fault energies in these systems decline modestly with temperature between 0 K and 1000 K.